Another "observation"... Each of the charging instances described below were with the iPhone below 20%, and then charging to 100%. Also, iPhone use was essentially the same. 1. For 2 consecutive days, I charged the iPhone at work through a power surge protector/suppressor. The iPhone charge lasted about 24 hours. I thought this was rather strange, since I've gotten closer to 36-48 hours before, but not paying attention to where or how I charged the iPhone. But I think that most of my charging was at home, and rarely at work. 2. 3rd day, I charged using the USB port on my computer. The iPhone lasted almost 48 hours. 3. Next 2 days, I charged at home, straight into the wall socket. Each time, the iPhone lasted almost 48 hours. 4. Finally, back at work, I charged directly through the wall socket. Again, the iPhone lasted almost 48 hours. It appears that charging through a power surge protector/suppressor has some kind of effect on how the battery charges... and therefore how long the charge holds? Any thoughts?